The completion in various construction phases
In 1182 CE, the choir was completed in the Romanesque style and consecrated. The crossing, the transept, and a large part of the nave were completed by 1190 AD. The western facade was sealed in 1225 CE, and the nave reached its final form. The crossing tower was erected in 1230 CE, and during this period, the construction of the two towers of the western facade began, which were finally completed in 1250 CE.
From around 1250 CE, the first documented remodelings began, which were inspired by the Gothic style. The Romanesque facades of the transepts were partially demolished and replaced with neo-Gothic elements to create a uniform overall appearance. Also, the buttresses of the choir were transformed from Romanesque to Gothic structures. Extensive modernizations took place inside the cathedral, stretching until 1363, shaping Notre Dame into a masterpiece of Gothic architecture.